We got an aqua cube, the 40 oz version from walmart for about $20.00 (USD) last year. It works ok, doesnt hold much water and the filters are expensive at about $1.50 a piece. I don't know how long the filters last because i just took it out instead of buying it. It has to be broken down and cleaned every month. (probably last longer if i put a filter in it.)
Anyways as I wrote this instructable the pump crapped out on me because it got gummed up with debris.
You will need:
A big watering dish. Don't get one of those tiny watering dishes for a little sissy lap animal, you want something for a big tiger. An American Tiger!. (3 bucks)
An aquarium filter. I have an aqua tech power filter i found with a fish tank on trash day. (they are $10 at walmart)
Water. Not that wimpy water that comes in a bottle but good ol TAP water. (free with my rent)
Step 1: Layout
My version utilizes an aquarium filter with a pet dish underneath.
In reality you need the biggest pet dish you can find.
This filter is designed for 5-10 gal aquarium.